Mining cutter bit



June 26, "1945. 7 H. M. STEPHENS 2,379,044-

MINING CUTTER BIT Filed Dec. 50,! 1940 I H5 ATTORNE Patented June 26, 1945 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to bitholders and particularly to a mining cutter bit used in connection with the mining of coal and ore or the like, Dr in such places as require the use of a bit of the type for cutting through a material, and has for its principal object the provision of an im proved construction of this character which is highly efficientin use and economical in manufacture.

The present invention relates to an improvement over that shown in my companion application filed on even date hereof, now Patent No. 2,305,040, issued December 15, 1942.

Among the salient objects of this invention is the provision of an effective and inexpensive arrangement for releasably holding and latching the bit to its chuck.

Heretofore in the employment of mining cutter bits of the type hereinafter described, due to the lack of firmness in holding the bit in place, a vibratory action would be transmitter to the bit, ultimately resulting in crystallization of the shank thereof and the breakage or dislodgement of the bit from its chuck or holder. In many instances in bits of the type hereinafter set forth, by virtue of the particular and special means adapted for holding the bit in its place upon the chuck, either the chuck or the shank of the bit, in order to make room for the attachment, was greatly weakened and often weakened to the point where, when the bit was subjected to rough usage, breakage at the line of weakened union occurred.

It is therefore one of the many objects of this invention to provide a bit which is attached to the chuck holder in a manner such as will prevent these known disadvantages.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing showing the preferred form of construction, and in which:

Fig. l is an edge view of the invention;

Fig. 2 is a plan sectional detail view of the same;

Fig. 3 is a fragmentary sectional detail view of the same showin the bit in partially removed position from its chuck or holder;

Fig. 4 is a sectional detail view of the same. taken substantially on lines 4.4 of Fig. 2;

Fig. 5 is a perspective view of the bit seen in Figs. 1 and 2 and inverted with respect thereto.

Referring now more particularly to the drawing showing the preferred form of construction of my invention, It indicates a holder or chuck having the usual eyebolt receiving bearings II which permit a plurality of the chucks I0 to be connected in chain formation for operation in a manner well-known in the mining art.

This chuck includes a passage l2 into which is slidably mounted a shank l3 having a tapering recess M. A set screw I5 is threadably carried by the holder l0 and is adapted to have its inner end portion 16 projected into the recess M. The arrangement is such that upon partially unthreading the set screw IS, the shank I3 may be partially withdrawn from the passage for the reasons hereinafter set forth and in the manner shown in Fig. 3.

'A tool holder is indicated at I! and is formed as an integral part of the shank I3. This tool holder 11 has a curved surface I8. formed in this tool holder a tapered tool receiving socket l 9, into which a tool, preferably in the form of a cutter bit 20, is adapted to be projected. 20 is provided with a tapered edge 2|.

Means is provided for releasably latching the cutter bit in the tapered socket l9. This means, in the present instance, comprises a saddle 22 pivotally mounted as at 23 to the side of the tool holder ll. Secured to the bight portion 24 of this saddle 22 is a latch dog 25 having opposite tapered end portions 26 and 21. The tapered end portion 26 is adapted to engage the tapered edge 2| of the cutter bit, while the tapered end 2! is adapted to engage the adjacent face 28 of the holder I0 when the shank I3 is locked in its extreme position'within the passage tion is created between the latching dog 2! and l the cutter bit 2| such that during the operation of the chuck holder the cutter bit 2| cannot be displaced or otherwise removed from the tool receiving socket.

In order to remove the cutter bit 20 from the tapered socket 19, it is necessary to partially withdraw the chuck I 9 to the position shown in Fig. 3.

This means for latching the cutter bit 20 in the tapered socket is highly efficient for the reason that no part of the tool holder cutter bit or chuck is weakened by the incorporation in the tool holder of the latching mechanism. It is of There is In the present instance, the cutter bit a structure which greatly facilitates the removal of the cutter bit with ease, yet prevents the withdrawal of this cutter bit 20 as long as the shank I3 is in its extreme position in the passage l2.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I therefore do not wish to be limited to the precise details of construction set forth, but desire to avail myself of, such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a tool head having a tapered socket, cutter bit mounted in the socket, a chuck, a shank on said head and slidably received in the chuck, and means for releasably connecting the shank of the chuck, the combination of latch means for said cutter bit, said latch means including a latch dog having opposite tapered end portions, one of said tapered end portions corresponding in taper to and being adapted to engage a tapered edge of the cutter bit, and the other tapered end of the latch dog being adapted to flatly engage an adjacent surface of the chuck when the shank is disposed in its extreme position in the chuck, and saddle means pivotally connected to the tool head exteriorly of said chuck and supporting said latch dog relative to said cutter bit and chuck.

2. In a tool head havin a tapered socket, a cutter bit mounted in the socket, a chuck, a shank on the tool head and slidably received by the chuck, and means for releasably connecting the shank to the chuck, the combination of latch means for said cutter bit said latch means comprising a latch dog having opposite tapered end portions, one of said tapered end portions being adapted to engage a tapered edge of the cutter bit, the other tapered end portion being adapted to engage an adjacent surface of the chuck when the shank is disposed in its extreme position in said chuck, a Ushaped saddle member having its bight portion connected to said latch dog and having the free ends of its leg portions embracing said tool head and pivotally connected to the latter exteriorly of the chuck to permit swinging movement of'said latch dog in a direction away from said cutter bit when the shank is partially withdrawn from said socket.

HENRY M. STEPHENS. 

